The Cell Culture and Genetic Engineering Core has two components: I. Cell culture component: Objectives of this component are to provide Liver Research Center Investigators with: (i) isolated liver cells of consistently high quality, (iii) well-characterized frozen stocks of cell lines, (iv) specialized culture media, hormones and supplements, and matrix components for optimal cell growth;and (iv) equipment and instructions for use in isolation and culturing of various cell types derived from the liver and II. Genetic Engineering component: (i) The objectives are to assist Liver Center Investigators in developing recombinant viral vectors, (based on oncoretroviruses, lentiviruses, adenoviruses and baculoviruses) for use in their specific research, and (ii) Maintain equipment for microscopy and assist in routine evaluation of cultured cells following genetic or other manipulations. Services to be added in 2008 include (i) culturing human embryonic stem cells and providing these to Liver Center Investigators for differentiation into liver cells;(ii) providing primary human liver cells isolated from resected liver segments and procured livers that are not used for transplantation;and (iii) assisting Investigators in genetically marking liver cells for identification after transplantation into animal models.